1. Field of the Invention
The present invention is used in the field of the backlighted display of large- or super-size LCD monitors, which requires parallel connection of multiple cold cathode fluorescent lamps (CCFLs) as light source. The high-frequency power source is typically supplied by an electronic ballast or power exchanger to ensure multiple cold cathode fluorescent lamps of single task working frequency, circuit stability, brightness efficiency, high quality and low distortion. The present invention provides measuring to such ends and serves as a protective device.
2. Description of the Prior Art
Typical application of CCFL as the backlighted display of LCD monitors requires an inverter and one or two CCFLs. When employed on large LCD monitors or large LCD TV screens, five to ten inverters may be required that will ensue the following drawbacks:                1. In case one of the tens of CCFLs is defective, the fault cannot be effectively detected, resulting in affecting LCD monitor quality;        2. As variations in high frequency exist among the inverters producing multiple frequency interferences to the LCD monitor, it increases the cost to introduce electromagnetic interference purging;        3. As multiple inverters' high-frequency voltage outputs will invariably vary, the brightness of CCFLs will be inconsistent, thus affecting the LCD monitor quality;        4. Cost of employing multiple inverters is higher than single electronic ballast or a single inverter.        
Thus, addressing foregoing deficiencies of typical application of CCFL as the backlighted display of LCD monitors, an innovative solution is proposed. A type of device functioning to measure and protect the circuits of CCFLs is designed so that when any one of tens of CCFLs fails, said device can effectively detect the defect to maintain the LCD monitor quality, while concurrently solving the typical multi-inverter practice's drawbacks of frequency interference, structural complexity and unnecessary high cost. These problems have long awaited for solutions by users and the inventor alike. After years of electronics related studies together with field research and development experience, aspiration arises to come up with an efficient solution. After repeated designing, investigating, model making and improving, a superior type of electronic device for measuring and protecting the circuits of CCFL has been designed specifically to address said problems.